3.0.0: Swift 5.0 and Xcode 10.2

Version 3.0.0 of Gagat migrates the project to Swift 5.0 and Xcode 10.2. There are no changes to the API in this release, but the project now requires Xcode 10.2 to compile.

Thanks once again to @douglashill for contributing these changes and keeping Gagat up-to-date!

2.0.0: Swift 4.2 and Xcode 10

Version 2.0.0 of Gagat migrates the project to Swift 4.2 and Xcode 10, and adds an Objective-C example app. There are no changes to the public API in this release, but the project now requires Xcode 10 to compile.
This is a breaking change compared to v1.1.0.

Thanks to @douglashill who contributed these changes!

1.1.0: Support for Objective-C!

Version 1.1.0 of Gagat adds support for Objective-C clients (i.e. using
Gagat from apps written in Objective-C)! See the README for instructions
on how to use Gagat from Objective-C.

There's also two new (optional) methods in GagatStyleable:
styleTransitionWillBegin() and styleTransitionDidEnd() which allow you
to do things right before a Gagat transition begins or right after it
ends. Thanks to @iKenndac for contributing these methods!

1.0.0: The first public release of Gagat!

Version 1.0.0 supports toggling between two alternative styles by
panning downwards using two fingers. The only configurable property is
the "jelly factor", which controls how much the transition edge is
deformed when dragging.